/*
 * Copyright (c) 2023, stelar7 <dudedbz@gmail.com>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include <AK/ByteBuffer.h>
#include <AK/String.h>
#include <LibCrypto/AEAD/ChaCha20Poly1305.h>
#include <LibTest/TestCase.h>

// https://datatracker.ietf.org/doc/html/rfc8439#section-2.6.2
TEST_CASE(test_keygen_vector_1)
{
    u8 key[32] = {
        0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
        0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f
    };
    u8 nonce[12] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 };
    u8 expected_raw[32] = {
        0x8a, 0xd5, 0xa0, 0x8b, 0x90, 0x5f, 0x81, 0xcc, 0x81, 0x50, 0x40, 0x27, 0x4a, 0xb2, 0x94, 0x71,
        0xa8, 0x33, 0xb6, 0x37, 0xe3, 0xfd, 0x0d, 0xa5, 0x08, 0xdb, 0xb8, 0xe2, 0xfd, 0xd1, 0xa6, 0x46
    };

    Crypto::AEAD::ChaCha20Poly1305 aead(ReadonlyBytes { key, 32 }, ReadonlyBytes { nonce, 12 });
    auto otk = MUST(aead.poly1305_key());
    auto expected = ReadonlyBytes { expected_raw, 32 };

    EXPECT_EQ(otk.bytes(), expected);
}

// https://datatracker.ietf.org/doc/html/rfc8439#appendix-A.4
TEST_CASE(test_keygen_vector_2)
{
    u8 key[32] = {
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
    };
    u8 nonce[12] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
    u8 expected_raw[32] = {
        0x76, 0xb8, 0xe0, 0xad, 0xa0, 0xf1, 0x3d, 0x90, 0x40, 0x5d, 0x6a, 0xe5, 0x53, 0x86, 0xbd, 0x28,
        0xbd, 0xd2, 0x19, 0xb8, 0xa0, 0x8d, 0xed, 0x1a, 0xa8, 0x36, 0xef, 0xcc, 0x8b, 0x77, 0x0d, 0xc7
    };

    Crypto::AEAD::ChaCha20Poly1305 aead(ReadonlyBytes { key, 32 }, ReadonlyBytes { nonce, 12 });
    auto otk = MUST(aead.poly1305_key());
    auto expected = ReadonlyBytes { expected_raw, 32 };

    EXPECT_EQ(otk.bytes(), expected);
}

// https://datatracker.ietf.org/doc/html/rfc8439#appendix-A.4
TEST_CASE(test_keygen_vector_3)
{
    u8 key[32] = {
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01
    };
    u8 nonce[12] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02 };
    u8 expected_raw[32] = {
        0xec, 0xfa, 0x25, 0x4f, 0x84, 0x5f, 0x64, 0x74, 0x73, 0xd3, 0xcb, 0x14, 0x0d, 0xa9, 0xe8, 0x76,
        0x06, 0xcb, 0x33, 0x06, 0x6c, 0x44, 0x7b, 0x87, 0xbc, 0x26, 0x66, 0xdd, 0xe3, 0xfb, 0xb7, 0x39
    };

    Crypto::AEAD::ChaCha20Poly1305 aead(ReadonlyBytes { key, 32 }, ReadonlyBytes { nonce, 12 });
    auto otk = MUST(aead.poly1305_key());
    auto expected = ReadonlyBytes { expected_raw, 32 };

    EXPECT_EQ(otk.bytes(), expected);
}

// https://datatracker.ietf.org/doc/html/rfc8439#appendix-A.4
TEST_CASE(test_keygen_vector_4)
{
    u8 key[32] = {
        0x1c, 0x92, 0x40, 0xa5, 0xeb, 0x55, 0xd3, 0x8a, 0xf3, 0x33, 0x88, 0x86, 0x04, 0xf6, 0xb5, 0xf0,
        0x47, 0x39, 0x17, 0xc1, 0x40, 0x2b, 0x80, 0x09, 0x9d, 0xca, 0x5c, 0xbc, 0x20, 0x70, 0x75, 0xc0
    };
    u8 nonce[12] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02 };
    u8 expected_raw[32] = {
        0x96, 0x5e, 0x3b, 0xc6, 0xf9, 0xec, 0x7e, 0xd9, 0x56, 0x08, 0x08, 0xf4, 0xd2, 0x29, 0xf9, 0x4b,
        0x13, 0x7f, 0xf2, 0x75, 0xca, 0x9b, 0x3f, 0xcb, 0xdd, 0x59, 0xde, 0xaa, 0xd2, 0x33, 0x10, 0xae
    };

    Crypto::AEAD::ChaCha20Poly1305 aead(ReadonlyBytes { key, 32 }, ReadonlyBytes { nonce, 12 });
    auto otk = MUST(aead.poly1305_key());
    auto expected = ReadonlyBytes { expected_raw, 32 };

    EXPECT_EQ(otk.bytes(), expected);
}

// https://datatracker.ietf.org/doc/html/rfc8439#section-2.8.2
TEST_CASE(test_aead_encrypt_1)
{
    auto plaintext = "Ladies and Gentlemen of the class of '99: If I could offer you only one tip for the future, sunscreen would be it."_string;
    u8 aad[12] = { 0x50, 0x51, 0x52, 0x53, 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7 };
    u8 key[32] = {
        0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
        0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f
    };
    u8 nonce[12] = { 0x07, 0x00, 0x00, 0x00, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47 };

    u8 expected_ciphertext[114] = {
        0xd3, 0x1a, 0x8d, 0x34, 0x64, 0x8e, 0x60, 0xdb, 0x7b, 0x86, 0xaf, 0xbc, 0x53, 0xef, 0x7e, 0xc2,
        0xa4, 0xad, 0xed, 0x51, 0x29, 0x6e, 0x08, 0xfe, 0xa9, 0xe2, 0xb5, 0xa7, 0x36, 0xee, 0x62, 0xd6,
        0x3d, 0xbe, 0xa4, 0x5e, 0x8c, 0xa9, 0x67, 0x12, 0x82, 0xfa, 0xfb, 0x69, 0xda, 0x92, 0x72, 0x8b,
        0x1a, 0x71, 0xde, 0x0a, 0x9e, 0x06, 0x0b, 0x29, 0x05, 0xd6, 0xa5, 0xb6, 0x7e, 0xcd, 0x3b, 0x36,
        0x92, 0xdd, 0xbd, 0x7f, 0x2d, 0x77, 0x8b, 0x8c, 0x98, 0x03, 0xae, 0xe3, 0x28, 0x09, 0x1b, 0x58,
        0xfa, 0xb3, 0x24, 0xe4, 0xfa, 0xd6, 0x75, 0x94, 0x55, 0x85, 0x80, 0x8b, 0x48, 0x31, 0xd7, 0xbc,
        0x3f, 0xf4, 0xde, 0xf0, 0x8e, 0x4b, 0x7a, 0x9d, 0xe5, 0x76, 0xd2, 0x65, 0x86, 0xce, 0xc6, 0x4b,
        0x61, 0x16
    };

    u8 expected_tag[16] = {
        0x1a, 0xe1, 0x0b, 0x59, 0x4f, 0x09, 0xe2, 0x6a, 0x7e, 0x90, 0x2e, 0xcb, 0xd0, 0x60, 0x06, 0x91
    };

    auto ciphertext = ReadonlyBytes { expected_ciphertext, 114 };
    auto tag = ReadonlyBytes { expected_tag, 16 };

    Crypto::AEAD::ChaCha20Poly1305 aead(ReadonlyBytes { key, 32 }, ReadonlyBytes { nonce, 12 });
    auto encrypted = MUST(aead.encrypt(ReadonlyBytes { aad, 12 }, plaintext.bytes()));

    EXPECT_EQ(encrypted.size(), plaintext.bytes().size() + 16);
    EXPECT_EQ(encrypted.bytes().slice(0, plaintext.bytes().size()), ciphertext);
    EXPECT_EQ(encrypted.bytes().slice_from_end(16), tag);
}

// https://datatracker.ietf.org/doc/html/rfc8439#appendix-A.5
TEST_CASE(test_aead_decrypt_1)
{
    u8 aad[12] = { 0xf3, 0x33, 0x88, 0x86, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x4e, 0x91 };
    u8 key[32] = {
        0x1c, 0x92, 0x40, 0xa5, 0xeb, 0x55, 0xd3, 0x8a, 0xf3, 0x33, 0x88, 0x86, 0x04, 0xf6, 0xb5, 0xf0,
        0x47, 0x39, 0x17, 0xc1, 0x40, 0x2b, 0x80, 0x09, 0x9d, 0xca, 0x5c, 0xbc, 0x20, 0x70, 0x75, 0xc0
    };
    u8 nonce[12] = { 0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08 };
    u8 ciphertext[265] = {
        0x64, 0xa0, 0x86, 0x15, 0x75, 0x86, 0x1a, 0xf4, 0x60, 0xf0, 0x62, 0xc7, 0x9b, 0xe6, 0x43, 0xbd,
        0x5e, 0x80, 0x5c, 0xfd, 0x34, 0x5c, 0xf3, 0x89, 0xf1, 0x08, 0x67, 0x0a, 0xc7, 0x6c, 0x8c, 0xb2,
        0x4c, 0x6c, 0xfc, 0x18, 0x75, 0x5d, 0x43, 0xee, 0xa0, 0x9e, 0xe9, 0x4e, 0x38, 0x2d, 0x26, 0xb0,
        0xbd, 0xb7, 0xb7, 0x3c, 0x32, 0x1b, 0x01, 0x00, 0xd4, 0xf0, 0x3b, 0x7f, 0x35, 0x58, 0x94, 0xcf,
        0x33, 0x2f, 0x83, 0x0e, 0x71, 0x0b, 0x97, 0xce, 0x98, 0xc8, 0xa8, 0x4a, 0xbd, 0x0b, 0x94, 0x81,
        0x14, 0xad, 0x17, 0x6e, 0x00, 0x8d, 0x33, 0xbd, 0x60, 0xf9, 0x82, 0xb1, 0xff, 0x37, 0xc8, 0x55,
        0x97, 0x97, 0xa0, 0x6e, 0xf4, 0xf0, 0xef, 0x61, 0xc1, 0x86, 0x32, 0x4e, 0x2b, 0x35, 0x06, 0x38,
        0x36, 0x06, 0x90, 0x7b, 0x6a, 0x7c, 0x02, 0xb0, 0xf9, 0xf6, 0x15, 0x7b, 0x53, 0xc8, 0x67, 0xe4,
        0xb9, 0x16, 0x6c, 0x76, 0x7b, 0x80, 0x4d, 0x46, 0xa5, 0x9b, 0x52, 0x16, 0xcd, 0xe7, 0xa4, 0xe9,
        0x90, 0x40, 0xc5, 0xa4, 0x04, 0x33, 0x22, 0x5e, 0xe2, 0x82, 0xa1, 0xb0, 0xa0, 0x6c, 0x52, 0x3e,
        0xaf, 0x45, 0x34, 0xd7, 0xf8, 0x3f, 0xa1, 0x15, 0x5b, 0x00, 0x47, 0x71, 0x8c, 0xbc, 0x54, 0x6a,
        0x0d, 0x07, 0x2b, 0x04, 0xb3, 0x56, 0x4e, 0xea, 0x1b, 0x42, 0x22, 0x73, 0xf5, 0x48, 0x27, 0x1a,
        0x0b, 0xb2, 0x31, 0x60, 0x53, 0xfa, 0x76, 0x99, 0x19, 0x55, 0xeb, 0xd6, 0x31, 0x59, 0x43, 0x4e,
        0xce, 0xbb, 0x4e, 0x46, 0x6d, 0xae, 0x5a, 0x10, 0x73, 0xa6, 0x72, 0x76, 0x27, 0x09, 0x7a, 0x10,
        0x49, 0xe6, 0x17, 0xd9, 0x1d, 0x36, 0x10, 0x94, 0xfa, 0x68, 0xf0, 0xff, 0x77, 0x98, 0x71, 0x30,
        0x30, 0x5b, 0xea, 0xba, 0x2e, 0xda, 0x04, 0xdf, 0x99, 0x7b, 0x71, 0x4d, 0x6c, 0x6f, 0x2c, 0x29,
        0xa6, 0xad, 0x5c, 0xb4, 0x02, 0x2b, 0x02, 0x70, 0x9b
    };

    u8 expected_plaintext[265] = {
        0x49, 0x6e, 0x74, 0x65, 0x72, 0x6e, 0x65, 0x74, 0x2d, 0x44, 0x72, 0x61, 0x66, 0x74, 0x73, 0x20,
        0x61, 0x72, 0x65, 0x20, 0x64, 0x72, 0x61, 0x66, 0x74, 0x20, 0x64, 0x6f, 0x63, 0x75, 0x6d, 0x65,
        0x6e, 0x74, 0x73, 0x20, 0x76, 0x61, 0x6c, 0x69, 0x64, 0x20, 0x66, 0x6f, 0x72, 0x20, 0x61, 0x20,
        0x6d, 0x61, 0x78, 0x69, 0x6d, 0x75, 0x6d, 0x20, 0x6f, 0x66, 0x20, 0x73, 0x69, 0x78, 0x20, 0x6d,
        0x6f, 0x6e, 0x74, 0x68, 0x73, 0x20, 0x61, 0x6e, 0x64, 0x20, 0x6d, 0x61, 0x79, 0x20, 0x62, 0x65,
        0x20, 0x75, 0x70, 0x64, 0x61, 0x74, 0x65, 0x64, 0x2c, 0x20, 0x72, 0x65, 0x70, 0x6c, 0x61, 0x63,
        0x65, 0x64, 0x2c, 0x20, 0x6f, 0x72, 0x20, 0x6f, 0x62, 0x73, 0x6f, 0x6c, 0x65, 0x74, 0x65, 0x64,
        0x20, 0x62, 0x79, 0x20, 0x6f, 0x74, 0x68, 0x65, 0x72, 0x20, 0x64, 0x6f, 0x63, 0x75, 0x6d, 0x65,
        0x6e, 0x74, 0x73, 0x20, 0x61, 0x74, 0x20, 0x61, 0x6e, 0x79, 0x20, 0x74, 0x69, 0x6d, 0x65, 0x2e,
        0x20, 0x49, 0x74, 0x20, 0x69, 0x73, 0x20, 0x69, 0x6e, 0x61, 0x70, 0x70, 0x72, 0x6f, 0x70, 0x72,
        0x69, 0x61, 0x74, 0x65, 0x20, 0x74, 0x6f, 0x20, 0x75, 0x73, 0x65, 0x20, 0x49, 0x6e, 0x74, 0x65,
        0x72, 0x6e, 0x65, 0x74, 0x2d, 0x44, 0x72, 0x61, 0x66, 0x74, 0x73, 0x20, 0x61, 0x73, 0x20, 0x72,
        0x65, 0x66, 0x65, 0x72, 0x65, 0x6e, 0x63, 0x65, 0x20, 0x6d, 0x61, 0x74, 0x65, 0x72, 0x69, 0x61,
        0x6c, 0x20, 0x6f, 0x72, 0x20, 0x74, 0x6f, 0x20, 0x63, 0x69, 0x74, 0x65, 0x20, 0x74, 0x68, 0x65,
        0x6d, 0x20, 0x6f, 0x74, 0x68, 0x65, 0x72, 0x20, 0x74, 0x68, 0x61, 0x6e, 0x20, 0x61, 0x73, 0x20,
        0x2f, 0xe2, 0x80, 0x9c, 0x77, 0x6f, 0x72, 0x6b, 0x20, 0x69, 0x6e, 0x20, 0x70, 0x72, 0x6f, 0x67,
        0x72, 0x65, 0x73, 0x73, 0x2e, 0x2f, 0xe2, 0x80, 0x9d
    };

    u8 expected_tag[16] = {
        0xee, 0xad, 0x9d, 0x67, 0x89, 0x0c, 0xbb, 0x22, 0x39, 0x23, 0x36, 0xfe, 0xa1, 0x85, 0x1f, 0x38
    };

    auto plaintext = ReadonlyBytes { expected_plaintext, 265 };
    auto tag = ReadonlyBytes { expected_tag, 16 };

    Crypto::AEAD::ChaCha20Poly1305 aead(ReadonlyBytes { key, 32 }, ReadonlyBytes { nonce, 12 });
    auto decrypted = MUST(aead.decrypt(ReadonlyBytes { aad, 12 }, ReadonlyBytes { ciphertext, 265 }));

    EXPECT_EQ(decrypted.size(), plaintext.size() + 16);
    EXPECT_EQ(decrypted.bytes().slice(0, plaintext.size()), plaintext);
    EXPECT_EQ(decrypted.bytes().slice_from_end(16), tag);
}

TEST_CASE(test_aead_encrypt_and_decrypt)
{
    auto plaintext = "Well, hello friends :)"_string;
    u8 aad[12] = { 0x50, 0x51, 0x52, 0x53, 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7 };
    u8 key[32] = {
        0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
        0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f
    };
    u8 nonce[12] = { 0x07, 0x00, 0x00, 0x00, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47 };

    Crypto::AEAD::ChaCha20Poly1305 aead(ReadonlyBytes { key, 32 }, ReadonlyBytes { nonce, 12 });
    auto encrypted = MUST(aead.encrypt(ReadonlyBytes { aad, 12 }, plaintext.bytes()));
    auto decrypted = MUST(aead.decrypt(ReadonlyBytes { aad, 12 }, encrypted.bytes().slice(0, encrypted.bytes().size() - 16)));

    EXPECT(Crypto::AEAD::ChaCha20Poly1305::verify_tag(encrypted, decrypted));
    EXPECT_EQ(decrypted.bytes().slice(0, encrypted.bytes().size() - 16), plaintext.bytes());
}
